how many ohms does it have? as far as i know svd still works on 1,3 ohm and vamo lowest ohms is 1,5. If your kayfun ohm is high enough, maybe its center pin fault. About the burn: do you tryed to vape with different juice in it? Its got to be problem in your ejuice or maybe you should try to rebuild your coil. Try to lift higher or lower your coil and if thats not helping, i think you should rebuild it.